The present invention is directed to cantilever bicycle brake devices.
Bicycles capable of off-road travel, such as MTBs (mountain bikes) are equipped with cantilever brake devices in order to provide strong braking force. Cantilever brake devices straddle both sides of the bicycle rim to provide braking action, and are generally equipped with a pair of left and right brake links and brake shoes attached to the brake links. The brake links are rotatably supported in cantilever fashion on the front and rear forks, and their top ends are connected to cable components which are split into two at their distal ends.
Cable component connection designs include the straddle cable design and the unit link design. In the straddle cable design, a straddle cable is linked through a metal hanger to the distal end of the inner cable, whose basal end is engaged by the brake lever, and both ends of the straddle cable are detachably linked to the brake links. With the straddle cable design, the brakes are adjusted by adjusting the inner cable attachment position using the metal hanger. The difficulty entailed in adjusting the attachment position has gradually led to the adoption of the unit link design.
In the unit link design, the distal end of the inner cable is screwed directly to the distal end of one of the brake links. A branch cable, termed a unit link, is connected at some point along the inner cable, and the distal end of this branch cable is detachably engaged by the other brake link. However, since the unit link design involves screwing one of the brake links to the distal end of the inner cable, when the unit link is disengaged from the other brake link, it sometimes happens that the first brake link does not open sufficiently towards the brake release position if the inner cable is not made sufficiently slack. When this happens, sufficient space between the wheel and the brake shoes is not maintained, and the wheel may come into contact with the brake shoes, making it difficult to remove.
To overcome this problem, one known design provides an anchor member secured to the distal end of the inner cable, wherein the anchor member is detachably engaged at the distal end of one of the brake links. The anchor member principally comprises a screw with a hexagonal hole and a cylindrical nut. A through hole which extends in the diametrical direction is made in the nut, and the inner cable is inserted through this through hole. The inner cable is pressed against the interior of the nut by the screw in order to secure the inner cable to the anchor member.
With the conventional cantilever brake device described above, when the wheel is to be removed from the fork, the unit link and the anchor member are disengaged from the two brake links. This allows the two brake links to be opened towards the brake release position, ensuring that there is sufficient space between the wheel and the break shoes to allow the wheel to be removed with ease. However, during brake adjustment, a wrench, screwdriver, or other tool must be used on the screw and nut while the anchor member is engaged by the brake link, and the length of the inner cable must be adjusted using these tools while manipulating the brake link and the inner cable. Thus, brake adjustment is difficult to perform alone, and is a fairly complicated operation.